Approximately 15% of couples attempting to conceive fail to do so within one year of unprotected intercourse. Fertility specialists define these couples as being infertile. 40% of these cases result from male factors. In a substantial proportion of these, treatment is available to ameliorate or relieve a condition which leads to infertility.
Other conditions also exist in which it is desirable to test for presence or otherwise of viable spermatozoa in a sample. For example, vasectomies are now frequently performed as a method of contraception, but it is necessary to confirm that ejaculate is free of viable spermatozoa after this operation.
A number of methods exist for assessing motility and number of spermatozoa in a sample. One such method is microscopic analysis, which is typically performed in a hospital or commercial laboratory. More recently, however, a number of proposals have been made for test kits which are intended to simplify detection of spermatozoa.
W097/40386 discloses a kit which is based on immunodetection of the 34 kDa human epididymal spermatozoa protein. Spermatozoa in a sample are washed three times by centrifugation in Dulbecco-phosphate buffered saline. These samples are then heat denatured at 95° C., centrifuged at 14000 g, and supernatants are then used for analysis.
W095/29188 describes a test based on antibodies applied to the SP-10 antigen of human spermatozoa.
EP-A-0387873 discloses a kit which uses solid beads to which are bound antibody specific to the human spermatozoon acrosome. The beads are mixed with a sample, incubated, separated and washed, and a number of spermatozoa bound to the beads is measured, preferably by examination with aid of a microscope.
A disadvantage of these test kits is that they do not distinguish between motile and non-motile spermatozoa. This distinction is a most predictive indicator of male infertility. Moreover, they involve procedures which do not lend themselves to home use (e.g. centrifugation, microscopy), thus requiring implementation by a skilled practitioner.
These disadvantages are addressed by the device of W000/09648 (Genosis Limited), which discloses an apparatus for separating motile spermatozoa from non-motile spermatozoa in a liquid sample, the apparatus comprising: (i) a vessel having a sample receiving inlet, a filtered sample outlet and a sample separation filter mounted therebetween, with the sample separation filter having a sample-receiving surface and an opposed surface, and the sample separation filter being effective substantially to prevent flow of a sample therethrough, but permitting passage of motile spermatozoa therethrough when the opposed surface of the sample separation filter is placed in contact with a liquid medium; and (ii) means for supplying a liquid to the opposed surface of the filter.
Further improvements in sperm separation, detection and analysis are disclosed herein.